This invention relates in general to explosively driven fasteners and deals more particularly with an improved self-propelled fastener assembly which carries an explosive charge and a primer to facilitate explosive driving.
Stud driving tools used to explosively drive fasteners into wood, concrete and steel structures have been known for many years. Tools of this type commonly employ an explosive cartridge to generate gas under high pressure for propelling fasteners through a barrel having a bore into which the fastener is loaded.
Heretofore, self-propelled fasteners have been proposed for use in such tools. Typical examples of such fasteners are found in the following listed U.S. patents.
U.S. Pat. No. 2,663,259, Catlin et al PA1 U.S. Pat. No. 2,944,261, Schulz et al PA1 U.S. Pat. No. 3,021,746, Marsh
However, such self-propelled fasteners as heretofore available are generally of somewhat unconventional design, have proven difficult and relatively expensive to produce and have not gained general acceptance. A self-propelled fastener which carries a propellent charge and a conventional shock detonated primer may prove potentially dangerous to handle. Where electrical ignition is employed to detonate the primer the potential risk of detonation by static electricity exists.
Accordingly, it is the general aim of the present invention to provide an improved self-propelled explosively driven fastener which carries an explosive charge and a primer, which may be economically produced and which is safer to handle and use than previously available self-propelled explosively driven fasteners.